Rangefinders can provide important data to aid a shooter in many applications, for example, hunting, competition shooting, military or law enforcement, in making precise shots on targets. Many conventional rangefinders use a laser beam to determine distance to an object by calculating the time it takes for a laser pulse of light to reach a target and be reflected back to the source. As computers have become more powerful and smaller, it has become increasingly popular to incorporate computers in laser rangefinders to provide ballistic data to the shooter based on a variety of parameters such as the specific rifle, bullet or environmental factors. One problem with such devices is that they can be cumbersome to program or customize because of the amount of data needed to be entered to provide accurate ballistics.
Most conventional ballistic rangefinders are one of two types. As shown in FIG. 1, the first type is a basic rangefinder 12 that uses generic ballistics formulas and computing with a relatively simple interface. Such basic rangefinders 12 do not need many buttons because there are not many features, although, as explained below, the menus for such basic rangefinders 12 can be cumbersome because of the limited button options. As shown in FIG. 1, the basic rangefinder has two buttons, namely a laser fire button 10 and a menu button 20, both of which are single position (press down) buttons. Actuation of the laser fire button 10 causes the basic rangefinder 12 to take measurements, such as the range, when in range mode. Actuation of the menu button 20 causes the basic rangefinder 12 to enter a menu mode wherein a limited number of options can be selected such as, LED screen brightness or ranging mode style. An example of this style of rangefinder menu entry can be found in the Vortex Optics Ranger 1000 Rangefinder. However, even entry of this limited information can be confusing due to the limited button press combinations. Some basic rangefinders 12 lump multiple bullet classes together and average them to provide a generic ballistic solution. For shorter range shots (less than 500 yards) this may be acceptable. For longer range shots or extremely precise shots, this is often not accurate enough.
The second type of rangefinder is a more advanced rangefinder 100 as seen in FIG. 2. Advanced rangefinder 100 allows the user to enter many variables, such as the bullet's ballistic coefficient, muzzle velocity, barometric pressure, elevation, bullet drag model, scope height, zero range, and a number of other factors to give an extremely precise ballistic solution to the user. However, entry of such data to initially set up existing advanced rangefinders 100 is cumbersome and confusing. As seen in FIG. 2, one such example of an advanced rangefinder 100 is the Gunwerks G7 BR2 rangefinder. This device has four different buttons, each of which are single position (press down). The user must press the laser fire button 110 to cause the advanced rangefinder 100 to take a measurement, or may press and hold the mode button 120 to access the menu mode. Once in the menu mode, the user needs to cycle through various main menu headings as well as adjust individual menu selections using the up arrow button 130 and the down arrow button 140. This requires pressing multiple buttons using two hands located at different positions around the device. The G7 BR2 is an advanced rangefinder, but is difficult to program. For example, to accurately calculate ballistic data specific to the user of that rangefinder, the user must input information into the device, including environmental factors such as wind speed and direction, in addition to information about the firearm being used, such as caliber, barrel twist, twist direction, muzzle velocity, etc. Finally, the user must also input information about the ammunition itself, including but not limited to ballistic coefficient, bullet weight, and bullet length. Further, advanced rangefinders 100, such as the G7 BR2, are more expensive due to the increased labor and manufacturing as a result of having more buttons and a larger form factor. Advanced rangefinder 100 is also more susceptible to liquid and debris entry because the large number of buttons provides a large number of entry points.
Another issue with typical laser rangefinders is that they do not allow a user to store information related to multiple set-ups. For example, if a shooter has multiple rifles, and he wants to use the same laser rangefinder for all of his guns, he must enter the entire set of data for available parameters into the rangefinder every time he switches guns. This can be a time consuming and frustrating process, especially if the user wants to switch guns with any frequency.
Yet another issue with existing rangefinders relates to the sophistication of the ballistics features. Some existing ballistics rangefinders offer generic ballistics formulae and computing in order to make the user interface easier, but these rangefinders are often not accurate or customizable enough for serious shooters. As a result, there is a need for a way to provide a feature-rich ballistic program in a package that is easy for users to input their customized data, and further allows the user to store such customized data for multiple gun/ammunition combinations.
To help with information input, some existing rangefinders that allow ballistic programming include many buttons, which makes them expensive to make and confusing to use. Additionally, including additional buttons necessitate a larger form factor device housing to provide adequate space for the buttons. The more confusing a rangefinder is, the less likely a user is to utilize all the available features, thereby making the user less accurate than he or she can otherwise be. Including additional buttons also often translates to an increase in expense, labor intensiveness, and difficultly to manufacture, and increases the number of entry points for liquid and debris to enter the rangefinder.
Other existing rangefinders have feature-rich ballistic programs, but offer only a couple of single position buttons. Such rangefinders are also confusing because it can be difficult to determine which buttons to press and in what order to enter the menu mode, to cycle menu options, or to cycle the menu option's setting. In particular, existing rangefinders do not have an intuitive way of inputting wind speed and direction. Therefore, there is a need for an easy to use rangefinder with a feature-rich ballistic program, but with as few intuitive buttons as possible to allow a user to navigate a display/menu layout that is easy to use.
Another difficulty with current ballistics rangefinders involves wind data. Wind is particularly noteworthy in shooting because wind can have a large effect on a bullet's trajectory, and because it is difficult to directly measure given that it is constantly changing. It would thus be advantageous to have a device or feature built into rangefinder that aids the user in keeping track of their wind direction and velocity. There currently are devices on the market that can directly measure wind, but they are large, expensive, or heavy on battery consumption. For example the Venom LX unit made by Torrey Pines reads real time wind for shooters. Although this device can calculate and track real time wind, it would be an advantage to hunters, military, and law enforcement personnel to have a similar feature, but was one that was inexpensive, portable enough to fit into a hand-held laser rangefinder, used little to no additional battery power, and easy enough to use that it kept track of wind data with minimal user inputs.
When reading wind data, the conventional method is to identify the direction the wind is coming from, followed by the wind velocity. For example, a wind of 360 degrees at 10 mph means that wind is coming from 360 degrees (due north) going to the south, at 10 mph. This convention is often misunderstood by a layman, where as a weather person, pilot, or someone who is required to know intimate details of weather, will understand this correctly. Because of this, it is important that the wind entry be intuitive to all people, and that there is no mistaking the wind direction.